As described in U.S. Pat. No. 6,829,808, which is herewith incorporated by reference, a known door hinge for recessed installation between an edge of a door panel and a door jamb has first and second housings that each form a cavity and are recessed in the door-panel edge and in the door jamb. A pair of U-section links pivoted centrally together about a center axis each have a first end and a second end engaged in the cavities of the respective first and second housings. The first end of one of the links and the second end of the other link are pivoted about respective vertical axes fixed in the respective housings and the second end of the one link and the first end of the other link are pivotal about another respective vertical axis and horizontally shiftable in a respective guide of the respective housings. Thus when the assemblies are fitted to respective mortises in the jamb and door edge, when the door is closed the hinge is not visible.
By providing an electrical connection assembly extending between the two housings, such hinges fasten doors not only invisibly on a door frame but also can be set up to connect electrical loads and sensors on them without a visible cable. Possible areas of use are, for example, electrical door locks, alarm systems, access monitoring systems, illumination devices and fire alarm systems.
A hinge with the above-described features is known from DE 10 2007 041 816. In this known hinge a ribbon cable extends through between the links of the link assembly and exits through holes on the back walls of the housings.
In a hinge known from US 2001/0026204 a flexible electrical connection assembly is provided that comprises electrical connectors on both ends. The connectors are connected to each other by a cable.
The known measures are expensive to assemble. Furthermore, the cable that runs through the link assembly can be damaged by uncontrolled intrinsic movements during actuation of the hinge.
This represents a serious danger for the functionality of the attached devices.